chart:= proc (head::list, vals::list, flag::boolean) 
  options `Maple Advisor Database 1.00 for Maple V Release 4 and 5`,
 `Copyright (c) 1997 by Robert B. Israel.  All rights reserved`; 
  if nargs = 3 and not flag then 
     MATRIX([head, seq(eval(subs(head[1] = vals[i],head)),i = 1 .. nops(vals))]) 
  else 
     MATRIX([head, seq(evalf(eval(subs(head[1] = vals[i],head))),i = 1 .. nops(vals))]) 
  fi 
end;